Vitamin C
Vitamin ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
A powerful antioxidant essential for collagen synthesis, immune function, and iron absorption. Humans cannot synthesize it and must obtain it from diet or supplements.
Exploratory record, not a reviewed medical publication.
See the editorial and medical-review policies for the publication gate.
This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
Vitamin C is a vitamin most often used for immune support, collagen synthesis, antioxidant protection. NutriStack rates the overall evidence as strong. A typical adult dose is 500–2,000 mg daily, commonly taken as ascorbic acid or liposomal vitamin c for higher absorption. This profile indexes 22 sources.
The bottom line
Evidence rating strong. Most-documented uses: immune support, collagen synthesis, antioxidant protection. 22 sources indexed (2004–2024), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
Acts as an electron donor, neutralizing free radicals. Required cofactor for prolyl and lysyl hydroxylases in collagen synthesis. Enhances non-heme iron absorption by reducing ferric iron to ferrous form. Supports immune cells including neutrophils and lymphocytes.
Dosing & protocol.
Water-soluble; split doses throughout day for better absorption1,3
What it actually costs.
Real-world pricing across three quality tiers. Assumes Ascorbic Acid.
Assumes about 500-1,000 mg/day. Plain ascorbic acid remains one of the best values unless GI tolerance is poor. Updated 2026-04-02.
The same dose, as food.
How much you'd eat to match a supplemental dose.
Food can easily cover modest vitamin C targets.
Higher supplemental-style doses are harder to match from food every day.
Full safety detail.
Side effects
- GI upset at high doses
- Diarrhea
- Kidney stones (rare, at very high doses)
Contraindications
- History of kidney stones (high doses)9
- Hemochromatosis
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
11- 1Vitamin C and E antioxidant supplementation may significantly reduce pain symptoms in endometriosis: A systematic review and meta-analysis of randomized controlled trials.PMIDBayu P, Wibisono JJ · PLoS One · 2024
Combined vitamin C and E supplementation significantly reduced chronic pelvic pain and dysmenorrhea in endometriosis patients.
- 2Vitamin C deficiency can lead to pulmonary hypertension: a systematic review of case reportsPMIDHemilä H, de Man AME · BMC pulmonary medicine · 2024
Hemilä H, de Man AME. Vitamin C deficiency can lead to pulmonary hypertension: a systematic review of case reports. BMC pulmonary medicine. 2024
- 3Efficacy of vitamin C supplementation in preventing and treating complex regional pain syndrome type I (CRPS-I) in Orthopedic patients: A systematic review and meta-analysisPMIDRanjbar Moghaddam M, Nasiri-Formi E, Merajikhah A · International journal of orthopaedic and trauma nursing · 2024
Ranjbar Moghaddam M, Nasiri-Formi E, Merajikhah A. Efficacy of vitamin C supplementation in preventing and treating complex regional pain syndrome type I (CRPS-I) in Orthopedic patients: A systematic review and meta-analysis. International journal of orthopaedic and trauma nursing. 2024
- 4Vitamin C reduces the severity of common colds: a meta-analysisPMIDHemila H et al. · BMC Public Health · 2023
Vitamin C significantly reduced the severity of common cold symptoms in placebo-controlled trials
- 5IV Vitamin C in Sepsis: A Latest Systematic Review and Meta-Analysis.PMIDWen C, Li Y, Hu Q et al. · International Journal of Clinical Practice · 2023
Intravenous vitamin C as adjunctive therapy in sepsis showed potential benefits in reducing inflammatory markers and improving organ dysfunction scores.
- 6Vitamin C intake and multiple health outcomes: an umbrella review of systematic reviews and meta-analysesPMIDChen Y et al. · Int J Food Sci Nutr · 2022
Umbrella review of systematic reviews examining multiple health outcomes of vitamin C including cardiovascular, immune, and cancer-related endpoints
- 7A Systematic Review on the Role of Vitamin C in Tissue HealingPMIDBechara N, Flood VM, Gunton JE · Antioxidants (Basel, Switzerland) · 2022
Bechara N, Flood VM, Gunton JE. A Systematic Review on the Role of Vitamin C in Tissue Healing. Antioxidants (Basel, Switzerland). 2022
- 8Parenteral Vitamin C in Patients with Severe Infection: A Systematic ReviewPMIDAgarwal A, Basmaji J, Fernando SM et al. · NEJM evidence · 2022
Agarwal A, Basmaji J, Fernando SM et al.. Parenteral Vitamin C in Patients with Severe Infection: A Systematic Review. NEJM evidence. 2022
- 9Ascorbic Acid Supplements and Kidney Stones Incidence Among Men and Women: A systematic review and meta-analysisPMIDJiang K et al. · Int J Food Sci Nutr · 2019
Vitamin C supplements were associated with significantly higher kidney stone incidence in men (OR 1.62) but not in women
- 10Vitamin C for preventing and treating the common coldPMIDHemila H, Chalker E · Cochrane Database Syst Rev · 2013
Regular vitamin C supplementation does not reduce common cold incidence in the general population but reduces duration; beneficial for those under heavy physical stress
- 11Effect of vitamin C supplementation on blood pressure: a meta-analysisSource linkedPMIDJuraschek SP, Guallar E, Appel LJ et al. · AJCN · 2012
Randomized controlled trials
1- 12Intravenous vitamin C as adjunctive therapy for severe COVID-19: a randomized controlled trialZhang J, Rao X, Li Y et al. · Crit Care · 2021
Reviews & position papers
8- 13Supplemental Vitamins and Minerals for Cardiovascular Disease Prevention and Treatment: JACC Focus Seminar.PMIDJenkins DJA, Spence JD, Giovannucci EL et al. · Journal of the American College of Cardiology · 2021
Evidence suggests vitamin C supplementation may have modest cardiovascular benefits through antioxidant mechanisms, though results from large RCTs are mixed.
- 14Vitamin C Intake and Cancers: An Umbrella ReviewPMIDChen Z, Huang Y, Cao D et al. · Frontiers in nutrition · 2021
Chen Z, Huang Y, Cao D et al.. Vitamin C Intake and Cancers: An Umbrella Review. Frontiers in nutrition. 2021
- 15Vitamin C supplementation and physical performance in trained athletes: a systematic reviewRighi NC, Schuch FB, De Nardi AT et al. · Nutrients · 2020
- 16Vitamin C and Immune FunctionPMIDCarr AC, Maggini S · Nutrients · 2017
Vitamin C supports epithelial barrier function, accumulates in phagocytic cells, enhances chemotaxis, phagocytosis, ROS generation, and killing; 100-200 mg/day needed for saturation
- 17The Roles of Vitamin C in Skin HealthPMIDPullar JM et al. · Nutrients · 2017
Skin contains high concentrations of vitamin C, which supports collagen synthesis and provides antioxidant protection against UV-induced photodamage
- 18Vitamin C supplementation for the primary prevention of cardiovascular disease: a Cochrane reviewAl-Khudairy L, Flowers N, Wheelhouse R et al. · Cochrane Database · 2017
- 19Vitamin C and immune function: a review of evidence from human and animal studiesCarr AC, Maggini S · Nutrients · 2017
- 20Enhancers of iron absorption: ascorbic acid and other organic acidsPMIDTeucher B et al. · Int J Vitam Nutr Res · 2004
Ascorbic acid is the most potent enhancer of nonheme iron absorption; reduces ferric to ferrous iron and reverses inhibitory effects of tea and calcium
Observational studies
1- 21Vitamin C supplementation and skin aging: a cross-sectional and prospective studyCosgrove MC, Franco OH, Granger SP et al. · AJCN · 2017
Reference material
1Common questions.
Quick answers about Vitamin C, drawn from the data on this page.
What is Vitamin C?
A powerful antioxidant essential for collagen synthesis, immune function, and iron absorption. Humans cannot synthesize it and must obtain it from diet or supplements.
What is Vitamin C used for?
Commonly cited benefits of Vitamin C include: Immune support; Collagen synthesis; Antioxidant protection; Iron absorption; Skin health. NutriStack rates the overall evidence as strong.
What is a typical dose of Vitamin C?
A typical adult dose of Vitamin C is 500–2,000 mg daily. The commonly recommended form is Ascorbic acid or liposomal vitamin C for higher absorption. These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of Vitamin C?
Reported side effects include gi upset at high doses, diarrhea, kidney stones (rare, at very high doses). This is educational information; check with a healthcare professional before use.
How strong is the evidence for Vitamin C?
NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Use this with your stack
Vitamin C in NutriStack.
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.